Oil film contamination of water bodies can cause heavy damage to aquatic life since the oil film retards penetration of oxygen into the water and oil washed up on beaches can destroy foreshore marine life.
A variety of proposals have been made to remove oil films from water. One such method involves the use of oil-absorbent materials which can be spread onto and float on the oil covered water to absorb the oil film. The oil-absorbent material then can be retrieved and the oil recovered or otherwise disposed of.
It has previously been suggested to employ peat in powdered form as such an oil-absorbent material. Peat, however, is hydrophilic in the natural state and hence, although peat absorbs oil on the surface of the water, a quantity of water also is absorbed, often causing the peat to sink. Accordingly, it has been considered necessary, therefore, to increase the hydrophobicity of the peat for use as an oil absorbent.
One such proposal is contained in Canadian Pat. No. 956,928 wherein it is indicated that peat with a decreased moisture content becomes hydrophobic and, accordingly, the patent proposes to decrease the water content of peat to below 10 wt. % for use as an oil-absorbent material.
Another proposal is contained in Canadian Pat. No. 1,160,201, wherein peat, at its natural moisture content of about 60 to 80 wt. %, is mixed with an alkaline earth metal material, notably calcium carbonate, the peat is partially dried to a moisture content of about 25 to 35 wt. %, the partially dried peat is mixed with further alkaline earth metal material, and the treated peat is dried further to a final moisture content of about 5 to 10 wt. %. The product is said to have a high hydrophobicity and to be capable of absorbing up to 20 times its own weight in oil. Treated peat prepared in accordance with this process is commercially available under the trade name "OCLANSORB" from Hi-Point Peat Ltd., Newfoundland, Canada.
Although hydrophobic peat is effective in absorbing oil from oil-contaminated water bodies and from other oil-contaminated surfaces without the concomittant problem of water absorbtion, a major problem lies in the physical form of the peat, namely its dry powder form. The dry peat is light and readily becomes airborne, rendering it often difficult to apply effectively to a large body of open water without significant wind losses, and also providing a significant fire hazard on storage and during indoor use.